GPIO-Based Robust Control of Nonlinear Uncertain Systems Under Time-Varying Disturbance With Application to DC–DC Converter

This brief considers the robust output-feedback control problem of a class of nonlinear uncertain systems subject to time-varying disturbances. For this purpose, a generalized proportional-integral observer (GPIO) together with a feedback domination approach is utilized for disturbance compensation and nonlinear uncertainty suppression. It is shown that the proposed control method can dominate the nonlinear uncertainties, by properly assigning a tunable scaling gain, and also remove the undesirable influences caused by a general class of time-varying disturbances through compensation design. An application design example of a dc-dc buck converter is presented to demonstrate the feasibility and efficacy of the proposed control approach.